The invention relates to systems and methods for geophysical data processing, and in particular to seismic imaging systems and methods.
Generating images of subsurface structures is a key component of the search for oil and gas deposits. Accurate imaging decreases the chances of drilling expensive dry wells, allowing a reduction in the cost of oil exploration and production, and a reduction in dependence on foreign oil.
Kirchhoff migration methods are commonly used for seismic imaging. In Kirchhoff migration, the energy of an event on a trace is propagated to all possible reflection points in the model space. After all events on all traces are propagated, an image is generated by stacking (summing) all individual contributions. Stacking reinforces in-phase energy corresponding to true reflectors, and cancels out-of-phase energy that does not correspond to a true reflector.
Conventional seismic imaging methods are generally computationally intensive and time-consuming. A turnaround time of 6-8 months is not uncommon for a medium to large depth imaging project corresponding to an area of a few hundred to a few thousand square miles. Speeding up the generation of accurate seismic images allows the 3D seismic data to be used more effectively to characterize and delineate oil and gas reservoirs and to monitor enhanced oil recovery processes, and decreases the probability of making drilling mistakes due to incorrect subsurface image and geopressure information.